Not Applicable.
Not Applicable.
The present invention relates to an antibiotic formulation. More specifically, the present invention relates to an antibiotic formulation that includes beta lactams in a true solution.
Historically, beta lactams are insoluble. Current formulations of beta lactams are sterile suspensions or sterile powders for suspension of corresponding salts. The sterile powder for suspension becomes a solution with the addition of diluents such as sterile water or saline.
One disadvantage associated with antibiotic drugs in sterile suspension formulations or sterile powders for suspension is that they cannot be filtered for sterility. If a suspension were filtered to remove impurities, the active pharmaceutical ingredient would be filtered out of the formulation and render the product inactive for its intended use.
A second disadvantage associated with antibiotic drugs in a suspension formulation is that sterile ingredients must be used in making the formulation. This is disadvantageous because sterile ingredients are more costly than non-sterile components. Also, using sterile ingredients makes the process for making the formulation time-consuming and labor intensive.
A third disadvantage associated with antibiotic drugs in suspension formulations is that uniform dosages are not necessarily obtained from such formulations because they may not deliver a constant, uniform amount of drug and liquid.
A fourth disadvantage associated with antibiotic drugs in suspension formulations is that the suspensions are both a solid and a liquid. Thus, solids settle out and fall to the bottom of the container over time. They become re-suspended only after agitation. In addition, over time solids can aggregate as a result of compaction and/or re-crystallization due to temperature fluctuations.
Further, a typical suspension diluent is sterile water, sterile saline or other sterile medium, which may freeze at temperatures below 0xc2x0 C. Therefore, an antibiotic in a sterile suspension must be warmed before administration when temperatures are below freezing.
In order to overcome these disadvantages, an antibiotic formulation in a true solution is needed.
It is an object of the present invention to provide an antibiotic formulation that is in a true solution so that it does not separate into solid and liquid components.
It is a further object of the present invention to provide a method of making an antibiotic formulation in true solution so that it may be filtered without removing the active ingredient.
It is yet another object of the present invention to provide an antibiotic formulation that can be administered without agitation so that it can be administered more quickly and easily.
Still another object of the present invention is to provide a method of making an antibiotic formulation using non-sterile manufacturing materials so as to save manufacturing time and costs.
It is another object of the present invention to provide an antibiotic formulation that can be administered without warming when temperatures are below freezing so that it can be administered more quickly and easily.
According to the present invention, the foregoing and other objects are achieved by an antibiotic formulation in a true solution. This formulation includes an antibiotic and N-methyl-2-pyrrolidone. It may also include an antioxidant, a preservative and/or an additive. The antibiotic is a beta lactam, such as a penicillin, a cephalosporin, other beta lactams, or combinations thereof. The formulation is made by dissolving the antibiotic in the N-methyl-2-pyrrolidone. The antibiotic formulation is suitable for use at temperatures below freezing and without agitation.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned from the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The formulation of the present invention is an antibiotic in a true solution. This formulation includes an antibiotic and a solvent. Optionally, a preservative, an antioxidant, and/or an additive may be added to the formulation.
The antibiotic used in the formulation is a beta lactam, such as a penicillin, a cephalosporin, other beta lactams, or combinations thereof. The penicillins that can be used in the formulation of the present invention include, but are not limited to, procaine penicillin G, benzathine penicillin G, amoxicillin, ampicillin, carbenicillin, piperacillin, ticarcillin, or combinations thereof The cephalosporins that can be used in the formulation of the present invention include, but are not limited to, ceftiofur, ceftiofur sodium, cefazolin, cefaclor, ceftibuten, ceftizoxime, cefoperazone, cefuroxime, cefprozil, ceftazidime, cefotaxime, cefadroxil, cephalexin, cefamandole, cefepime, cefdinir, cefriaxone, cefixime, cefpodoximeproxetil, cephapirin, cloxacillin, or combinations thereof. Preferably, if a cephalosporin is included, ceftiofur sodium is used. Other beta lactams that can be used in the formulation include, but are not limited to, aztreonam, cefotetan, loracarbef, cefoxitin, meropenem, imipenem, or combinations thereof.
The solvent used in the formulation of the present invention is a pyrrolidone solvent, namely, N-methyl-2-pyrrolidone (NM2P).
It is desirable to add a preservative to the formulation of the present invention. The preservative that may be used in the formulation of the present invention can be, but is not limited to, benzyl alcohol, ethyl alcohol, parabens such as methyl, ethyl and/or propylparaben, chlorobutanol, sodium benzoate, benzoic acid, myristyl-gamma-picolinium chloride, benzathonium chloride, or combinations thereof. Preferably, benzyl alcohol is used if a preservative is used in the formulation. Preferably, a preservative is added to the formulation if a beta lactam is used as the antibiotic in the formulation.
The antioxidant that may be used in the formulation of the present invention can be, but is not limited to, edetate disodium, sodium metabisulfite, sodium formaldehyde sulfoxylate, vitamin E acetate, vitamin C, vitamin B12 or combinations thereof.
The additive that may be used in the formulation of the present invention can be, but is not limited to, 2-pyrrolidone, N-5-dimethyl-2-pyrrolidone, 3-3-dimethyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-ethyloxy-2-pyrrolidone, N-ethylene-2-pyrrolidone, pyrrolidone, glycerol formal, propylene glycol, polyethylene glycol, glycerine, water, and combinations thereof.
The antibiotic formulation is made by first warming the N-methyl-2-pyrrolidone. Preferably, the NM2P is warmed to about 30-50xc2x0 C. Most preferably, the NM2P is warmed to about 35-45xc2x0 C. The antibiotic is added to the NM2P, and the mixture is stirred until the antibiotic dissolves. The mixture is then cooled. Preferably, it is cooled to at least about 30xc2x0 C. A preservative, antioxidant, and/or additive may then be added to the mixture, and the mixture is stirred. Additional NM2P may be added to further dilute the formulation, if desired, or to fully dissolve the antibiotic.
The antibiotic is about 5-50% by weight of the true solution. Preferably, it is about 15-40% by weight of the true solution. Most preferably, it is about 20-30% by weight of the true solution.
The total amount of preservative in this formulation is about 0-15% weight per volume of the solution (w/v). Preferably, a preservative is present in an amount of about 0.02-10% w/v. Most preferably, a preservative is about 0.5-3% w/v of the formulation. If included, the antioxidant is about 0.5-10% w/v of the solution. If included, preferably, the antioxidant is about 1-5% by w/v of the solution.
The antibiotic formulation of the present invention is a true solution. Therefore, it can be formulated from non-sterile manufacturing materials and can be filtered to remove contaminants.
In addition, by being a true solution, it is more readily available and quickly absorbed. Therefore, it is more quickly available to enter tissues and be biologically available. In contrast, biological absorption from suspensions of the prior art is dependent upon drug particle size. The true solution of the present invention removes the potential problem of particle size variation.
Further, the antibiotic formulation of the present invention can be administered to a target species below about 0xc2x0 C. In fact, it does not freeze until it is at temperatures below about xe2x88x9220xc2x0 C. Still further, the antibiotic formulation of the present invention can be administered without being agitated before use.
It is specifically contemplated that this formulation can be administered to animals including, but are not limited to, bovines, ovines, porcines, felines, canines and/or ungulates. For this reason, it is especially useful that the formulation easily can be administered at cold temperatures so as to treat animals that are outside in the winter. The formulation can be administered orally, parenterally, or topically.
The following are examples of the antibiotic formulation of the present invention and methods of making these formulations. Examples 1-3 illustrate making an antibiotic formulation with beta lactams in a true solution. Example 4 illustrates making a cephalosporin formulation in a true solution. These examples are not meant in any way to limit the scope of this invention.